Data centre cooling apparatus

ABSTRACT

Embodiments of the present invention provide a data centre, comprising data centre air directing means for directing data centre air from the data centre through a first side of one or more heat exchangers; external air directing means for directing external air from external to the data centre through a second side of the one or more heat exchangers; and adiabatic cooling means for adiabatically cooling the external air prior to entering the one or more heat exchangers, such that the external air flowing through the second side of the one or more heat exchangers indirectly cools the data centre air flowing through the first side of the one or more heat exchangers. Embodiments of the present invention may be realised in which the data centre is a moveable data centre.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims priority to and benefit of Great Britain patent application 0818404.6 filed Oct. 8, 2008, the disclosure of which is incorporated herein in its entirety by reference.

BACKGROUND

Currently, the storage of sensitive information, such as credit card numbers and Data centres are environments in which computing equipment is located. Typically, a data centre houses a plurality of computers arranged in fixtures, such as racks. Each computer may include a combination of components, such as one or more processors and associated memory devices, storage devices such as magnetic or optical based storage devices, and one or more communication devices.

Due to the concentration of computing equipment in a data centre, cooling is required in order to maintain a temperature within the data centre under an acceptable level. However, data centre cooling consumes a significant amount of energy and may also require significant infrastructure support. In the case of a moveable data centre, such as that portably housed within a container or the like, suitable infrastructure support may not be available at a location at which it is desired to operate the data centre.

It is known to cool data centres by means of mechanical refrigeration-based systems including air conditioning units arranged inside the data centre. For example, direct expansion (DX) or chilled water air conditioning systems are often utilised in data centres. However, such systems require significant installation effort and have high running costs. In some data centres, it has been determined that a Power Utilisation Effectiveness (PUE), calculated by total data centre energy consumption/computing equipment energy consumption, was 2.15, which equates to the cooling energy accounting for approximately 38% of the energy expended on running the data centre.

It is an object of embodiments of the invention to at least mitigate one or more of the problems of the prior art.

BRIEF DESCRIPTION OF THE DRAWINGS

The accompanying drawings, which are incorporated in and form a part of this specification, illustrate embodiments of the present technology for securing data centre cooling, together with the description, serve to explain principles discussed below.

FIG. 1 is an illustration of a data centre cooling system according to an embodiment of the present invention.

FIG. 2 shows an example psychrometric chart.

FIG. 3 shows an example embodiment of a moveable data centre according to an embodiment of the present invention.

FIG. 4 shows another example embodiment of a moveable data centre according to an embodiment of the present invention.

FIG. 5 shows a further example embodiment of a moveable data centre according to an embodiment of the present invention.

FIG. 6 shows a still further example embodiment of a moveable data centre according to an embodiment of the present invention.

FIG. 7 shows an example plan-view of an external air channel of an embodiment of the present invention.

FIG. 8 shows a horizontal cross-section through an example embodiment of a moveable data centre.

The drawings referred to in this description should not be understood as being drawn to scale unless specifically noted.

DESCRIPTION OF EMBODIMENTS

Reference will now be made in detail to embodiments of the present technology, examples of which are illustrated in the accompanying drawings. While the present technology will be described in conjunction with various embodiment(s), it will be understood that they are not intended to limit the present technology to these embodiments. On the contrary, the present technology is intended to cover alternatives, modifications and equivalents, which may be included within the spirit and scope of the various embodiments as defined by the appended claims.

Furthermore, in the following detailed description, numerous specific details are set forth in order to provide a thorough understanding of embodiments of the present technology. However, embodiments of the present technology may be practiced without these specific details. In other instances, well known methods, procedures, components, and circuits have not been described in detail as not to unnecessarily obscure aspects of the present embodiments.

Referring to FIG. 1, a cooling system 100 for use with a data centre according to an embodiment of the invention is shown.

A data centre 110 represents a substantially enclosed volume, such as one or more rooms, in which computer equipment is operatively located. Typically, the computer equipment comprises one or more servers, data storage devices and communications equipment, although the present invention is not limited in this respect.

The data centre 110 comprises one or more air outlets 120 through which data centre air is exhausted from the data centre 110. In the embodiment shown, the data centre 110 comprises one outlet 120, although it will be realised that other numbers of outlets may be envisaged. In some embodiments, air may be forcibly expelled from the data centre 110 by means of one or more fans located either within the data centre 110, in a mouth of each outlet 120, or in a mouth of an inlet. The outlet 120 is in fluid communication with an inlet 130 via a data centre air circuit 140 through which air extracted from the data centre 110 is cooled and returned to the data centre 110 at a lower temperature.

The data centre 110 is internally segregated or divided into cool and warm air portions. Airflow is generally unidirectional from the cool portion to the warm portion. Airflow between the cool and warm portions is directed via the computer equipment to provide cooling thereto, such that the air entering the warm portion is at a higher temperature than that in the cool portion.

The data centre air circuit 140 comprises one or more air-to-air heat exchangers 142, 143. In the shown embodiment, the data centre air circuit comprises two heat exchangers 142, 143, although other numbers of heat exchangers may be envisaged. In some embodiments, the heat exchangers 142, 143 are counter-flow plate-type heat exchangers. Airflow through the data centre air circuit 140 is directed through a primary side of each heat exchanger 142, 143 whilst external air is directed through a secondary side of each heat exchanger 142, 143, such that the heat exchangers 142, 143 operatively reduce the temperature of the air from the data centre 110 passing there-through. The data centre air circuit 140 may further comprise a fan 141 to circulate air around the data centre air circuit 140. In some embodiments, the fan 141 may be a variable speed fan to control a speed of airflow through the data centre air circuit 140. For example, depending upon a ratio of data centre air temperature to the temperature of cooled external air flowing through the opposing side of the heat exchanger, a relative speed of airflow may be changed by the fan, such that cooling of the data centre air is improved.

An external air circuit 150 of the cooling system 100 comprises an air intake 151 through which air external to the data centre 110 enters the external air circuit 150, an outlet 152 through which air is exhausted from the external air circuit 150 and an adiabatic cooler 154. The adiabatic cooler 154 operates to cool air passing there-through by an adiabatic process. Adiabatic cooling of the air passing through the external air circuit 150 is achieved through humidification of the air passing through the adiabatic cooler 154. In some embodiments, adiabatic cooling may be performed through a spray process whereby a mist of water droplets is sprayed into the external air passing through the adiabatic cooler 154. However, in other embodiments, the adiabatic cooler 154 comprises a water supply providing water to a porous membrane to keep the membrane wet. Airflow through the adiabatic cooler 154 is passed through or over the membrane such that evaporation of the water held therein takes place. A decrease in the temperature of the air passing through the adiabatic cooler 154 takes place as a humidity of the air increases.

In the embodiment shown in FIG. 1, the external air circuit 150 also comprises a filter 153, a fan 155 and a mixing damper 156. The filter 153 removes, at least partially, debris and/or bacteria present in the air entering the external air circuit 150. In the embodiment shown in FIG. 1 the filter 153 is arranged between the inlet 151 and the adiabatic cooler 154. However, it will be realised that the filter 153 may be arranged in other locations within the external air circuit 150 and that further filters 153 may be provided. The mixing damper 156 is present in a recirculation channel or duct of the external air circuit 150 running between a post heat exchanger 142, 143 portion of the external air circuit 150 and a portion prior to the adiabatic cooler 154. The mixing damper 156 operatively controls airflow through the recirculation channel to control the temperature of air entering the adiabatic cooler 154. The fan 155 is arranged to circulate air around the external air circuit 150. In the embodiment shown in FIG. 1 the fan is arranged between the adiabatic cooler 154 and the first heat exchanger 143, although it will be realised that other locations of the fan 155 may be used appropriately depending upon space requirements etc. In some embodiments, the fans 141, 155 may be variable speed fans to control a speed of airflow through one or both of the data centre air circuit 140 and/or external air circuit 150 to increase an operating efficiency of the cooling system 100 depending upon the temperature of the external air and/or of the data centre air.

A method of operating the system of FIG. 1 will now be described with reference to FIGS. 1 and 2.

FIG. 2 shows a psychrometric chart 200 of dry-bulb temperature against absolute humidity. One line 210 indicates a temperature and humidity of air at two points in the data centre air circuit 140, whilst another line 220 indicates a temperature and humidity of air at three points in the external air circuit 150. Saturation is indicated by line 230. It will be realised that the temperature and humidity figures described with reference to FIG. 2 are merely for illustration of the operation of the present invention.

The air entering the external air circuit 150 via the inlet 151 is external or outside air at a prevailing ambient temperature and moisture content. For example, air at point 1 indicated within a circle in FIGS. 1 and 2 may have a temperature of 20° C. and a moisture content of 50%. The air passes through the filter 153 to remove airborne debris and/or bacteria. Air in the external air circuit 150 then passes through the adiabatic cooler 154, which reduces the temperature and increases the moisture content of the external air by adiabatic cooling. For example, air leaving the adiabatic cooler 154 at point 2 may have a temperature of 15° C. and a moisture content of 90%, as shown particularly in FIG. 2. Meanwhile, air is being moved around the data centre air circuit 140 from the outlet 120 to the inlet 130 of the data centre 110. By way of an example, air leaving the data centre at point 4 in FIGS. 1 and 2 may have a temperature of 30° C. and a moisture content of 40%. Air moving around the data centre air circuit 140 passes through a data centre side of the heat exchangers 142, 143 whilst the air moving through the external circuit 150 passes through an external air circuit side of the heat exchangers 142, 143. The external air circuit 150 air absorbs heat from data centre air passing through the data centre air side of the heat exchangers 142, 143, thus indirectly cooling air in the data centre air channel 140. It will be noted that the data centre and external channels in the heat exchangers 142, 143 are separate. That is, air in the data centre and external air circuits 140, 150 respectively do not mix. The temperature of the air entering the data centre 110 at point 5 in FIGS. 1 and 2 may have a temperature of 17° C. and a moisture content substantially equal to that leaving the data centre 110, whereas air leaving the external air circuit prior to the outlet 152 has a temperature of 27° C. and a moisture content substantially equal to that at point 2. Thus, air moving around the data centre air circuit 140 is cooled indirectly by the air moving around the external air circuit 150, which is consequently heated, between the inlet 151 and outlet 152.

The mixing damper 156 prevents excessive cooling and/or dehumidification of the air passing around the data centre air circuit 140 due to the external air having an ambient temperature, which is too low. For example, if the external air has a low ambient temperature, for example of 1° C., then excessive cooling and/or dehumidification of the air in the data centre air circuit 140 may occur. To prevent this, the mixing damper 156 regulates a flow of air in the recirculation channel. When the external air has an ambient temperature, which is below a predetermined value, a portion of the air moving toward the outlet 152 is recirculated to mix with air prior to entering the adiabatic cooler 154 to increase the temperature of that air. Thus a temperature differential between the air flowing through opposing sides of the heat exchangers 142, 143 is reduced which prevents excessive cooling/dehumidification of air in the data centre side of the heat exchangers 142, 143.

Advantageously, embodiments of the present invention provide cooling to the data centre 110 at most times with reduced energy consumption requirements. Embodiments of the present invention do not, depending upon location and climatic conditions, require cooling of water or refrigerant. It is envisaged that embodiments of the present invention have a PUE of around 1.2-1.3. This would result in an energy saving of approximately 75% over conventional refrigeration based systems. As a consequence, the cooling energy would account for approximately 15% of the energy expended in running the data centre. Furthermore, isolation of the data centre air circuit 140 reduces a possibility of external pollution entering the data centre 110 and it is not required for air conditioning units to be located inside the data centre 110, thus increasing a useable area inside the data centre 110.

It is envisaged that embodiments of the present invention will provide sufficient cooling for the data centre 110 at most times. However, at some times, depending on a geographical location of the data centre 110 and/or a time of year, the temperature of the external air may be sufficiently high that adiabatic cooling does not sufficiently reduce the temperature of the external air to sufficiently cool the data centre air. Therefore, a supplementary cooling coil may be included in the data centre air circuit 140, for example between heat exchanger 143 and inlet 130, to selectively aid cooling of the data centre air. The supplementary cooling coil may be a direct expansion type, or a chilled water type, as will be appreciated by those skilled in the art.

An embodiment of the present invention for cooling a moveable data centre will now be described with reference to FIG. 3.

A moveable data centre may in some embodiments be a containerised data centre wherein computer equipment may be housed within a shipping container type structure. In other embodiments, a moveable data centre may by be a wheel-mounted container, such as a wagon or truck trailer. Other moveable data centres may be those mounted on or within a vessel, such as a ship. A moveable data centre may also be known as a portable on-demand data centre.

Referring to FIG. 3, the moveable data centre 300 comprises first 310 and second 320 compartments arranged in vertical relation. The first compartment 310 houses computer equipment 311 and is segregated into cool 312 and warm 313 air portions. Although the cool 312 and warm 313 air portions are shown in FIG. 3 as being of substantially equal size, this is merely for illustration purposes. The computer equipment 311 in FIG. 3 may be mounted in one or more rack structures, as is known in the art. The rack structures in the embodiment shown in FIG. 3 are closed cabinet structures wherein air is drawn into the cabinet through a front face and expelled through a rear of the cabinet. In order to segregate the cool 312 and warm 313 portions of the first compartment 310, blanking plates are used to avoid air recirculation from the warm portion 313 to the cool portion 312 via unused rack slots. Similarly, a divider is arranged in an area above each rack to segregate the cool 312 and warm air portions 313. It will also be noted that in some embodiments the front face of the cabinet is horizontally aligned with a rear face of the first heat exchanger 321 and a rear of the cabinet is aligned with a front face of the second heat exchanger 322. Air is communicated substantially unidirectionally from the cool portion 312 to the warm portion 313 via the computer equipment 311 where the air absorbs heat generated by the computer equipment 311.

The second compartment 320 is arranged below a floor 314 of the first compartment 310. An air outlet 315 is arranged in the floor 314 of the warm air portion 313 to allow warm air to be exhausted into the second compartment 320. An air inlet 316 is provided in a region of the floor 314 adjacent to the cold portion 312 of the first compartment 310 to allow cooled air to enter the first compartment 310 from the second compartment 320. Thus, cool air flows from the cool portion 312 through the computer equipment 311 absorbing heat there-from as it passes into the warm portion 313 of the first compartment 310. Warm air is exhausted from the first compartment 310 via the outlet 315 into the second compartment 320 and cooler air re-enters the cool air portion 312 of the first compartment 310 having been cooled in the second compartment 320.

A first heat exchanger 321 is arranged below the air inlet 316. A second heat exchanger 322 is arranged below the outlet 315. In some embodiments, the first and second heat exchangers 321, 322 are air-to-air cross-flow heat exchangers. The heat exchangers 321, 322 may be plate-type heat exchangers. The first and second heat exchangers 321, 322 are arranged in an external air channel 323. In some embodiments, the external air channel 323 is substantially linear between opposing sides of the data centre 300. First compartment 310 air is arranged to flow through a primary side of each heat exchanger 321, 322, whilst external air is arranged to flow through a secondary side of each heat exchanger 321, 322. The heat exchangers 321, 322 each operate to indirectly transfer heat from air exhausted from the first compartment 310 to external air. Air leaving the primary side of the second heat exchanger 322 is directed into a data centre air channel 330 below the external air channel 323 in the second compartment 320. Air flow in the data centre air channel experiences a turning motion through substantially 180° to enter the first heat exchanger 321. The fan 327 operates to drive air from the warm air portion 313 downward through the second heat exchanger 322 through the second compartment and upward through the first heat exchanger 321 into the cool air portion 312.

Air external to the data centre 300 enters the external air channel 323 via an inlet 324 at a first end thereof and flows through the external air channel 323 passing through the secondary side of each heat exchanger 321, 322. An adiabatic cooler 326 is arranged in the external air channel 323 prior to the first heat exchanger 321. The adiabatic cooler 321 is arranged to cool external air entering the external air channel 323 by an adiabatic process, as described with reference to the preceding embodiment. Thus, the external air flowing through the external air channel 323 is cooled prior to entering the first heat exchanger 321 to absorb heat from the airflow of the first compartment 310 passing through the primary side of the heat exchangers 321, 322. A first fan 327 is arranged below the second heat exchanger 322 to draw air through the second heat exchanger 322 from the warm portion 313 of the first compartment 310. A second fan 328 is arranged in the external air channel 323 between the first and second heat exchangers 321, 322 to move air through the external air channel 323 and heat exchangers 321, 322. In some embodiments, the first and second fans 327, 328 are variable speed fans to control a speed of airflow through the heat exchangers 321, 322 for optimum heat transfer. In order to efficiently direct air in the data centre air channel 330 between the first and second heat exchangers 321, 322 one or more airflow directors 329, such as turning vanes, may be arranged in the data centre air channel 330 to direct airflow there-through.

With reference to FIGS. 2 and 3, external air enters the external air channel 323 at point 1 in FIG. 3 having a temperature and humidity as indicated at point 1 in FIG. 2. A temperature of the external air is then reduced by the adiabatic cooler 326 whilst the humidity of the external air is increased at point 2, as shown in FIG. 2. The temperature of the cooled external air is then increased by its passage through the secondary side of each heat exchanger 321, 322 until the air is exhausted from the external air channel 323 to an exterior of the data centre 300 at point 3 having a temperature and humidity as indicated in FIG. 2. Meanwhile, data centre air having a relatively high temperature leaves the warm air portion 313 of the data centre via the outlet 315 as indicated at point 4 in FIGS. 2 and 3. The air re-entering the first compartment 310 into the cool air portion 312 at point 5 has a lower temperature than the air leaving at point 4 due to its cooling as it passes through the primary side of the heat exchangers 321, 322.

A further embodiment of the present invention will now be described with reference to FIG. 4.

A moveable data centre 400 is divided vertically into first 410 and second compartments 420. A construction of the data centre 400 is as in the last-described embodiment 300 unless otherwise stated and comprises upper and lower compartments 410, 420, first and second heat exchangers 421, 422, with a fan 428 there-between, and an adiabatic cooler 426 arranged in an external air channel 423 comprising an inlet 424 and outlet 425. Below the external air channel 423 is a data centre air channel 430 allowing the circulation of air from the upper compartment 410 between the heat exchangers 421, 422 that is aided by a fan 427 below the second heat exchanger 422. Air circulates from a warm air portion 413 of the upper compartment 410 via an outlet 415 in a floor 414 of the upper compartment 410 and is returned to a cool air portion 412 of the upper compartment 410 via an inlet 416.

In contrast to the previously described embodiment, computer equipment 411 is mounted in an open-cabinet support structure wherein the computer equipment 411 is suspended in spaced-apart relation without enclosure. In order to segregate the cool 412 and warm 413 air portions of the upper compartment 410, a front-face region of the open-cabinet forms a vertically extending barrier from floor to ceiling which separates the cool 412 and warm 413 air portions. Advantageously, this arrangement allows larger heat exchangers 421, 422 to be used. The front-face of the open cabinet is arranged in alignment with a rear of the first heat exchanger 421 so that cool air there-from is expelled into the cool air portion 412. However, since the open-cabinet does not comprise a rear wall, the second heat exchanger 422 is able to extend under the open-cabinet and computer equipment 411, thus allowing larger heat exchangers 421, 422 to be used.

Referring to FIG. 5, a further embodiment of the present invention is shown. For clarity, certain aspects of this embodiment will only be briefly described and the reader is directed to the description of equivalent features in the previously described embodiments.

A moveable data centre 500 is shown which comprises first 510 and second 520 compartments, wherein the first compartment houses computer equipment 511 as in the previously described embodiments. However, the first compartment 510 is arranged in vertical alignment below the second compartment 520 and divided there-from by a ceiling 514 of the first compartment 510. As in previously described embodiments, the first compartment 510 is divided into cool 512 and warm 513 air portions with substantially unidirectional airflow there-between via the computer equipment 511.

An external air channel 523 is arranged in a lower region of the second compartment 520 and comprises first 521 and second 522 heat exchangers, and an adiabatic cooler 526 prior to the first heat exchanger 521 to cool external airflow entering an inlet 524 of the external air channel 523. External air is exhausted through an outlet 525 of the external air channel 523 at an opposing end thereof from the inlet 524. The second heat exchanger 522 is located above the warm portion 513 of the first compartment 510 and the first heat exchanger 522 is located above the cool portion 512 of the first compartment 510. Data centre air leaving the second heat exchanger 522 enters a data centre air channel 530 in an upper region of the second compartment 520, before entering the first heat exchanger 521. A first fan 527 is arranged above the second heat exchanger 522 to draw air upward from the warm portion 514 through a secondary side of the second heat exchanger 522. A second fan 528 is arranged between the first and second heat exchangers 521, 522 to drive the flow of external flow through the external air channel 523 via the first and second heat exchangers 521, 522.

Warm air present in the warm air portion 513 is caused to naturally rise through the second heat exchanger 522 into the data centre air channel 530, thus less assistance may be provided by the first fan 527 to the data centre airflow due to a thermosyphon effect. As data centre airflow leaves the second heat exchanger 522 it naturally falls, due to its cooling, and is directed through the first heat exchanger 521 into the cool portion 512 of the first compartment 510.

Referring to FIG. 6, a further embodiment of the present invention is shown. Again, for brevity, certain details of the embodiment will not be further described and the reader is directed to the previously described embodiments.

A moveable data centre 600 comprises first 610 and second 620 compartments. The first and second compartments 610, 620 are arranged in side-by-side arrangement. The first compartment 610 is divided into cool 612 and warm air 613 portions. Computer equipment 611 is supported in a mounting structure, such as a rack, which partially defines the cool air portion 612 along with associated dividers to segregate the cool air portion 612 from the warm air portion 613. Air flows from the cool air portion 612 to the warm air portion 613 via the computer equipment 611, such that it cools the computer equipment 611. The second compartment 620 is generally vertically divided by first and second heat exchangers 621, 622 into an external air channel 623 and a data centre air channel 630. An inlet 624 of the external air channel 623 is arranged in a lower region of the second compartment 620 and an outlet 625 of the external air channel 623 is arranged in an upper region of the second compartment 620. The inlet 624 and outlet 625 of the external air channel are arranged in an end face of the data centre 600. The external air channel 623 comprises a fan 628 to circulate external air from the inlet 624 to the outlet 625 via the external air channel 623 and primary sides of the first and second heat exchangers 621, 622. Air is caused to, at least partially, naturally move between the inlet 624 and outlet 625 along the external air channel due to the relative vertical arrangement of the inlet 624 and outlet 625 and the heating of air as it passes through the heat exchangers 621, 622. Meanwhile, air from the warm air portion 613 of the first compartment 610 enters a primary side of the second heat exchanger 622 and is cooled as it passes there-through before travelling in a generally downward direction through a data centre air channel 630 in the second compartment which is located in a end region thereof. Data centre air passes through the secondary side of the first heat exchanger 621 and enters the cool air portion of the first compartment 612. A fan 627 is arranged in the cool air portion 612 to direct airflow through the computer equipment 611, to the warm air portion 613 and through the heat exchangers 621, 622.

As noted previously, in certain conditions, particularly when the external air is of a sufficiently low temperature with respect to the data centre air, excessive cooling of the data centre air and/or dehumidification thereof may occur. In order to at least partially ameliorate this, an embodiment of the present invention will be described with reference to FIG. 7. The embodiment described with reference to FIG. 7 provides further details of the recirculation channel and mixing damper described earlier with reference to FIG. 1.

FIG. 7 shows a plan view of an embodiment of an external air channel 723. The external air channel 723 comprises one or more recirculation paths or channels 740 having a mixing damper 741 arranged therein to control a recirculation of warmed air to an inlet of a first heat exchanger 721. In some embodiments, the external air channel 723 may comprise a single recirculation channel, although the described embodiment comprises two recirculation channels 740 and it will be realised that other numbers of recirculation paths are possible.

As shown in FIG. 7 the external air channel 723 comprises first and second heat exchangers 721, 722 with a fan 728 arranged there-between and an adiabatic cooler 726, as in previously described embodiments. An inlet 724 is arranged at a first end of the external air channel 723 and an outlet 725 is arranged at a second, distal, end of the external air channel 723. The one or more recirculation channels 740 are provided to allow recirculation of warm air to mix with cold air adjacent to an inlet of the first heat exchanger 721. In the shown embodiment, a pair of recirculation channels 740 is arranged along each side of the external air channel 723 to allow a recirculation of warm air from adjacent to the outlet 725 to an area adjacent to the inlet 724 within the external air channel 723. That is, relatively warm air output from the second heat exchanger 722 is recirculated to an input of the first heat exchanger 721. The recirculated warm air mixes with inducted external air to increase a temperature of air entering the first heat exchanger 721. Thus, excessive cooling and/or dehumidification of data centre air flowing through a primary side of the heat exchangers 721, 722 can be prevented. In order to control an amount of warm air passing through the recirculation channels 740, the mixing damper 741 is arranged in each channel 740 to variably control a cross sectional area of each recirculation channel 740. The mixing damper 741 is variably moveable between a first position in which it closes the recirculation channel 740, as shown in FIG. 7, and a second position in which is poses minimal obstruction to the recirculation channel 740. Thus, the mixing damper 741 allows control over the amount of warm air recirculated to the first heat exchanger 721.

FIG. 8 shows a horizontal cross section through a moveable data centre 800. The cross-section is shown at a level, which intersects external air channels 823 of the data centre 800. As shown in FIG. 8, the moveable data centre 800 comprises a plurality of external air channels, which extend across a width of the data centre 800. In the shown embodiment, the data centre 800 comprises four external air channels 823, although it will be realised that fewer or more external air channels 823 may be incorporated in embodiments of the data centre 800. Each external air channel 823 comprises first and second heat exchangers 821, 822 having a fan 828 arranged there-between. An adiabatic cooler 826 is arranged prior to the first heat exchanger in each external air channel 823 to cool external air inducted into the external air channel.

Although embodiments of the present invention have been described with reference to data centres which house a single row of racks or cabinets therein, embodiments of the present invention may be envisaged which house two or more rows of racks or cabinets. The two or more rows may be arranged substantially parallel or perpendicular to a direction of airflow.

All of the features disclosed in this specification (including any accompanying claims, abstract and drawings), and/or all of the steps of any method or process so disclosed, may be combined in any combination, except combinations where at least some of such features and/or steps are mutually exclusive.

Embodiments of the present invention provide a data centre, an apparatus and method for cooling a data centre, which allow efficient cooling of the data centre air to be performed.

Each feature disclosed in this specification (including any accompanying claims, abstract and drawings), may be replaced by alternative features serving the same, equivalent or similar purpose, unless expressly stated otherwise. Thus, unless expressly stated otherwise, each feature disclosed is one example only of a generic series of equivalent or similar features.

The invention is not restricted to the details of any foregoing embodiments. The invention extends to any novel one, or any novel combination, of the features disclosed in this specification (including any accompanying claims, abstract and drawings), or to any novel one, or any novel combination, of the steps of any method or process so disclosed. The claims should not be construed to cover merely the foregoing embodiments, but also any embodiments, which fall within the scope of the claims. 

1. A data centre, comprising: data centre air directing means for directing data centre air from the data centre through a first side of one or more heat exchangers; external air directing means for directing external air through a second side of the one or more heat exchangers; and adiabatic cooling means for adiabatically cooling the external air prior to it entering the one or more heat exchangers, such that the external air flowing through the second side of the one or more heat exchangers indirectly cools the data centre air flowing through the first side of the one or more heat exchangers.
 2. The data centre of claim 1, comprising recirculation means for controllably allowing at least some of the external air to recirculate through the second side of the one or more heat exchangers.
 3. The data centre of claim 1, wherein the data centre is a moveable data centre.
 4. The data centre of claim 3, wherein the data centre air directing means comprises a region of the moveable data centre separated from a region of the data centre storing computer equipment.
 5. The data centre of claim 3, wherein the external air directing means comprises an external air channel arranged between first and second opposing sides of the data centre.
 6. The data centre of claim 5, wherein the adiabatic cooler and the one or more heat exchangers are arranged in the external air channel.
 7. The data centre of claim 2, wherein the recirculation means comprises at least one recirculation channel arranged generally alongside the external air channel having a mixing damper arranged therein for controllably allowing air from proximal to an outlet of the external air channel to recirculate to an area of the external air channel proximal to an inlet thereof.
 8. The data centre of claim 1, wherein a region of the data centre storing computer equipment is segregated into cool and warm air portions and airflow between the cool air portion and the warm air portion is substantially via the computer equipment.
 9. The data centre of claim 8, comprising an outlet arranged in a warm air portion of the region of the data centre storing computer equipment to exhaust data centre air there-from, a conduit to direct the data centre air through the first side of the one or more heat exchangers to an inlet arranged in the cool air portion.
 10. The data centre of claim 5, wherein the external air directing means comprises a plurality of external air conduits each having an adiabatic cooling means and one or more heat exchangers arranged therein.
 11. The data centre of claim 1, wherein the adiabatic cooling means comprises means for increasing a moisture content and lowering a temperature of the external air passing there-through.
 12. The data centre of claim 11, wherein the adiabatic cooling means comprises one of a porous medium having water supplied thereto or spray means for spraying water droplets into the external air.
 13. An apparatus for cooling air from a data centre, comprising: one or more heat exchangers having at least two separate channels there-through, a first channel of the one or more heat exchangers for receiving an airflow from the data centre and a second channel of the one or more heat exchangers for receiving a second airflow; and one or more adiabatic coolers for cooling the second airflow prior to it entering the second channel of the one or more heat exchangers.
 14. The apparatus of claim 13, comprising a recirculation channel for allowing at least some of the second airflow to recirculate through the second channel of the one or more heat exchangers.
 15. The apparatus of claim 14, wherein the recirculation channel comprises a mixing damper for operatively controlling a passage of air there-through.
 16. The apparatus of claim 13, comprising a conduit for receiving external air, channelling the external air to the adiabatic cooler and the one or more heat exchangers, and exhausting at least some of the external air.
 17. The apparatus of claim 16, comprising at least one fan arranged in the conduit for moving external air there-through.
 18. The apparatus of claim 13 comprising at least one fan for circulating air from the data centre, through the first channel of the one or more heat exchangers and returning the air to the data centre.
 19. A method of cooling a data centre, comprising: directing external air through at least one adiabatic cooler to reduce a temperature whilst increasing a humidity of the external air; directing air output from the at least one adiabatic cooler to a first side of one or more heat exchangers; and directing air from the data centre to a second side of the heat exchanger separate from the first side, such that heat is absorbed from the data centre air flowing through the second side by air flowing through the first side.
 20. The method of claim 19, comprising recirculating at least some of the external air output from the one or more heat exchangers to the adiabatic cooler. 